Material fatigue is a common phenomenon where structures fail when subjected to a cyclic load. Material fatigue can impact the lifespan, availability, reliability and safety of operation of machinery, such as gas turbine engines (GTE). Material fatigue can result in damage to and eventually the failure of machinery components.
In engine structural life computations, it is common to designate a lifespan for certain components based on a certain number of start-stop cycles and based on a standard flight or missions. This lifespan designation is often done during the design process and involves detailed calculations of stresses and temperatures for a standard flight, and the use of material property and fatigue models. The limitation of the design phase calculations and life span designations are that they cannot take into account actual operating conditions. This limitation can result in conservative life span estimates and subsequent change of remaining engine life span or engine damage due to different operation or operational conditions that were not considered during design.
Some existing methods for determining fatigue life consumption adopt a physics-based approach that is comparable to the design phase lifespan designation. The physics-based approach can be computationally intensive and involves relying on a representative set of operating periods or field missions to evaluate fatigue life limits of machinery components. Analogous to the design phase lifespan designation, these existing methods may not be ideal for near real-time or real-time application and do not include characteristics to account for actual operating conditions, such as flight data or engine performance, which can be considered and used to extend availability, reliability, and safety of operation of GTEs.